Protective device for electrical apparatus.



J. E. MATEER.

PROTECTIVE DEVICE FOR ELECTRICAL APPARATUS. APPLICATION FILED JULY 17,1912.

11 86,81 5 Pawnted June 13, 1916.

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UNITED STATES PATENT OFFICE.

JESSE E. MATEER, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSEELECTRIC AND MANUFACTURING COMPANY, A CORPGRATION OF PENNSYLVANIA.

PROTECTIVE DEVICE F03, ELECTRICAL APPARATUS.

Application filed July 17, 1912.

To all whom it may concern:

Be it known that I, Jnssu E. MA'runu, a citizen of the United States,and a resident of VVilkinsburg, in the county ofAllegheny and State ofPennsylvania, have invented a new and useful Improvement in ProtectiveDevices for Electrical Apparatus, of which the following is aspecification.

My invention relates to protective devices for electrical apparatus,such as highpotential transformers, circuit-breakers, etc., andparticularly to devices that are employed in connection with terminalsof such apparatus for protecting the same from high-potentialdisturbances and for precluding the concentrations thereupon of staticlines of force or stresses.

The object of my invention is to provide a device which shall be simpleand compact in construction and which shall serve the functions of both.a static shield and a choke coil for distributing the static flux andfor damping high potential disturb-- tour which extend laterally fromthe ends.

of the leads and serve as enlargements thereof for the purpose ofdistributing the static lines of force or stresses, and preventing theirconcentration upon comparatively small areas. The said plates or diskstherefore serve as static shields. Also, in order to dampen and reducehigh-frequency and high-potential electrostatic discharges, and tothereby avoid injury to the insulation of the transformer or otherdevice, it is customary to connect a choke coil in series with the leadsof the said devices. The static shield and the choke coil haveheretofore been separate and distinct devices, each performing its ownfunction, but, according to the present invention, both functions areperformed by a single device which is more compact and economical inconstruction and occupies less space than two separate devices.

My invention is illustrated in the accompanying drawing, Figure 1 ofwhich is a plan view of a part of a transformer pro- Specification ofLetters Patent.

Patented J line 13, 1916.

Serial No. 710,034.

yided with a device constructed in accordance therewith. Fig. 2 is aside view of the transformer, portions of the protective device beingsaown in section, and Fig. 3 is an enlarged sectional view through apart of the protective device.

The device is here shown as employed in connection with a high-potentialtransformer 1 having a conducting lead or ter' minal 2 that projectsthrough its cover and is surrounded, and insulated from the cover, by aninsulating bushing 3, that is preferably constructed, of alternatelayers of insulating material and tin-foil, such as is disclosed inPatent No. 952,513. The upper end of the lead 2 extends beyond the bushing 8, and is immediately surrounded by a conducting sleeve or bushing lthat fits the same sufficiently closely to make a good electricalcontact therewith, but which is capable of rotation with respectthereto. The bushin g i 18 mounted in and surrounded by a wooden orother suitable insulating disk 5, the sides of which are preferablycovered with tin-foil 6 or some other suitable conducting material. Theinsulating disk 5 is surrounded by a flat spirally wound coil. 7 ofconducting ribbon or strap 8, the convolutions of which are insulatedfrom each other by means of strips of suitable insulating material 9 ofsomewhat greater width than the conductor 8, and the protruding sides ofwhich are folded inwardly to provide compact insulating coverings forthe otherwise exposed edges of the strap 8. The inner nd of the coil isseated in a notch or recess in the insulating disk 5, and it is alsoconnected, by means of a suitable strap or jumper 10, to the conductingbushing 4t, it being, by this means, connected to the end of the lead 2.The outer end. of the coil is soldered, or otherwise connected, to theouter convolution of the coil to form a complete ring, and a second ringof con ducting tubing 11 is closely fitted upon, and electricallyconnected to, the said outer convolution. Before the ring 11 is appliedto the coil, the coil is preferably treated with an insulatingcomposition which enters the pores and spaces therein and sets orhardens so as to cement the layers thereof together, and to render thecoil self supporting, when mounted in a horizontal position, a suitablematerial for treating the insulation being bakelite. A conductor 12rhich is de ice to high po;

transformer, is soldered .1 or other-n1. ii 3 connected to the ring or131 1 ii, and, bv reason ot the tact that the coil rotativelv nionntedupon the end of the conductor :3, t may be led directly said deviceirrespective its location to tln nsioriner.

be readh ui ood that coil.

T. ii'liich interposed former and iiet'l'ed, co

lis out i the transit conil, \vhich iotential .nicli 111a) transformerld urtherinore,

A; coil constitutes a static sh '-a which distributes the static i .cesdensity, the ring or 111,1 0 impart a smooth contour to the disk at d tothereby n concentation of po tential stress i claim as injr inventionit. The conihina "in with a conductor and an dating a surrounding theconductor, or a -cr :tendinn tlat coil pt sod at one end 01 the hrshingand elecdlv connected to sa d conductor to serve actance uevice aid alsoas a s atic bushing said conductor to so an l. also 21S- static ,1

connected to ca ctance levice $3. The coin nati on r; l a conductor andan, insul bi'lshing oi? a coil lotions e3:-

2' and elec cted to said condilctor, said so shap d as to insure asubstanbution of electrostatic aces of the bushing and ea ctance device.

uctirp; i saio cal com o. The combination with a conducting lead, o' cilat coil mounted upon and electrically conne tcd to said lead, and aconducting "iin oi curved cross section for said coil h an electricalconnection thereto. (3. nation with a conducting lean, "it coil embeddedin insulating material and provided with a conducting rini, said coilbeing inounted upon the lead and having its respective ends connected tothe lead and to the rim.

7. The combination with a conducting lead, oi. a Hat coil mounted uponand extending transversely to the lead and having its inner endconnected thereto, the said coil being; embedded in, and retained inshape by, insulating material, and a conducting rini niounted upon thecoil and connected to its outer end.

The combination With a conducting lead, and an insulating bushingsurrounding the same. of a spirall vvound coil rotatively mounted uponand extending transversely to the lead and having its inner endconnected thereto, the said coil being embedded in, and retained inshape by, insulatingmaterial, and a conducting rnn mounted upon andconnected to its outer end.

combination ivith a conducting the Gill W 9. inc

connected to outer end.

10. The combination with a conductor and an insulating bushingsurrouiuling the con ductor, of a coil supported upon. one end oi thebushing and electrically connected to said conductor to se "ie as a'eactance device, said coil being so positioned that the of theflux-volume generated by the current flow through the coil issubstantially parallel to the axis of the bushing.

The combination with a conducto and an insulat' bushing surrounding theconductor, ot' a coil supported upon one end of the bushing, laterallyextending therefrom and electri =all connected to said conductor toserve as a reactance device, said coil COll1- prising c nvolutions theplanes of which are substantially perpendicular to the axis of thecashing. 4

The combination with a conducto and an insn atingbushing therefor, of allat coil s ipported upon one end or the bushing, exing laterallytherefrom and electrically ted to said conductor to serve as a actancedevice, the plane oi said coil being bstantiall perpendicular to theaxis of e bushing. in testimony whereof, subscribed my name this 1912.

I have hereunto 3rd da of July JESSE E. MATEER.

llitnesses Cwonnoz; A. BUna, B. B. Hixns.

be obtained for five cents each, by addressing the Gommissioncx 0fl'atcnns,

Washington, G.

